Diana 460 accuracy question

[Zachary]

I have the Diana 460 as mentioned with close to 500 rounds through it. I have the RWS one piece mount with an Athlon Argos  4-20x50 on it. I’m shooting crossman premier hp in .177.  The question I have is that I’ll be shooting good like shooting the handle off a plastic spoon at 30 yards and hitting pretty much whatever I aim at. After maybe 15-20 shots give or take all the sudden it’ll be off maybe an 1” or so any given direction. I’ll sight it back in and it’ll be good for awhile and then it’ll happen all over again. I tried a Vortex Diamond Back scope with the same results. Is it me the gun or scope? Any ideas or advice would be appreciated.

[ER00z]

It could be the scopes not holding zero, or the mount slipping (or scope slipping in the mount?). Also, I'm not sure how your 460 is tuned, but in .177, Crosman hollow points are light for the factory power output (7.9gr in a 20+fpe gun).  If you could get your hands on some 10.5-ish grain pellets, you might find a smoother shot cycle and bring pellet velocity down some, both of which may help with consistent accuracy.

You may get suggestions on using different mounts and/or optics. My Diana 460 .177 has gone through a few variations in power levels and has seen a few optics. Currently it's putting out slightly over 20fpe, has a RWS drooper mount and a Burris fullfield optic, which seems to be holding up well.

I'm sure others will be along to assist further, best wishes in getting things sorted out.

[Jeff Marshall]

Have you checked to see if your stock screws are tight?

[Roadworthy]

If the only change you make to fix the misbehavior is to adjust your scope something within the scope may be drifting or your mount is not secure on the gun - something like that.  You may find a heavier pellet will reduce your recoil a bit but possibly not enough to eliminate whatever's happening with your optics.  The gun has enough recoil that I put a Diana Bullseye ZR (zero recoil) mount on my 460.

[Zachary]

As close as I can tell all the screws and the mounts are staying tight so far. I need to check again to make sure. I’ll look into some heavier pellets and a damper mount.

[lefteyeshot]

How does it shoot after the miss? If it's shoots okay after the miss it was a flyer. That's you. If it contunues to be off but still groups ok scope moved. And 21 perfect shots is hard to do.

[Zachary]

Sometimes it’s just a flyer. But some of the time it groups just like it did before just off from where it was. I can’t shoot groups like you guys even close but when my general cluster moves an 1” something seems off especially when I can move it back by adjusting the scope and it’ll be okay again for awhile. I’m thinking the scope isn’t holding but I’m not sure yet.

[A moron]

Seeing your gun has open sights , id set up and shoot with them  at the dame yardage.

At least 20+ yards.   Get good open sight zero so to say and see if you get that same results as scoped.

Ive had scopes do kinda like you say  and best i found id the rectical will spring off or creep after time.

Like hit zero well then go take a drink break or somthing and be gone 30min+/-. Comw back and the poi be off just like you say.

Id join ke wile i was gone someone snuck over and turned my turrets...lol

Then one that so many shots it seemed the rectical just jumped off  out of the blue.

Anyway all said and done i dont scope anymore 98%  of the time, just occasionally to yest somthing quick and easy hen go back open sight.   

That scope and springer chase got old  ...lol

[Zachary]

That’s exactly what I’m dealing with. I’m gonna try a zr mount and see what happens

[Jeff Marshall]

Does your barrel droop requiring the scope to be far from being optically centered?
That could be a problem.

[Zachary]

Not sure how far from being centered it is. How do I check? The mount has built in compensation.

[mpbby]

As a first thing, always have in mind how a scope internally works.

https://life.hawkeoptics.com/riflescope-alignment/

To resist properly, and after zeroing, the scope has to remain within its 'comfort zone'; rule of thumb = for each tower, maximum of +- 1 turn from the "optical center".

So, center the scope and see how much adjustments you are needing until zero.

In practice, the mirror method seems to me much easier to center, and it's close enough to the V-method.

After zeroing, and if you are out of the scope's comfort zone, you may consider the mount (more compensation?), the barrel (if it has a relevant droop, you may bend it to reduce).

Hawke also sells inserts to put inside the rings and reduce the vertical adjustments needed to zero. 

[Novagun]

It just may be that you have a bad barrel. I would put a pellet in the breech and get a piece of stout monofilament line. Say heavy weed eater line and push a pellet through to the muzzle. Test to see if the bore is consistent.Not lose and tight spots. If the bore is not consistent from muzzle to choke then the rifle will never shoot consistently.
I would be surprised if a 460 has muzzle droop. That shouldn't happen with a fixed barrel .
I know because I am waiting for a full refund warranty claim on a new Diana with a bad barrel.

[Tater]

Moved to the German Gate.

[Toxylon]

With the German springers, and magnums especially, 500 pellets is at the mere beginning of the break-in process. After shooting about three large tins, or 1 500 pellets, should one start evaluating a new gun's performance in earnest. Been there, etc.

[Mark 611]

First off, a gun in this power range is not meant for light pellets at full power! there's not enough pellet weight to offset the pressure needed to keep the piston from slamming at the end of the stroke with a lightweight pellet!  a 10.5gn pellet should be a minimum starting pellet weight for a rifle of this power range IMO, With the power the 460mag generates light weight pellets are going to destroy your optics!!! Unless you have a really expensive springer rated scope? My advice to you is to shoot the 10.5gn or a tic heavier if you plan to keep the rifle at full power? if you want to shoot the lightweight pellets due to accuracy reasons or cost? I would detune the rifle! chasing after expensive mounts to keep from destroying your scope is a band aid and will probably still destroy a cheaper optic with a mount like you're looking at, these types of threads are why I do not recommend guns of this power class in a .177cal at all just for the reasons posted in this thread! and from my own experience's, even with a 10.5gn and a good tune the rifle will still shoot around 950fps, just my thoughts!

[Yogi]

Are you sure you are not canting those shoots?

-Y

[ER00z]

After scrolling through posts, I have to ask does this gun have the PG4 kit in it?

If so, it seems like its making 15-16Fpe depending on the pellets used (Crosman 10.5's or 7.9's). If you can, try H&N FTT 8.6gr pellets in 4.52mm or JSB 8.4's, either/or should keep you in a fairly high velocity range without over driving pellets. My Diana's in .177 tend to like the H&N's... And can be had at a fairly decent price from FieldSupply or WingSupply (same company), also among other suppliers.

If you want to up the velocity some for heavier (10.5gr) pellets, add a thick washer to the piston, ahead of the kits top hat (the OEM one should work fine). If you find the Crosman 10.5's loose in the chamber, H&N Baracuda 4.52's or Baracuda Hunters usually fit nice and snug. 

I've found for best accuracy, keep velocity in the 860-890-ish fps zone, but some guns can get away with 900-920fps. On calm days I could push H&N Baracuda Hunters @ 935 fps "ok", but groups would open up down range with any kind of headwind. Hopefully if you get the ZR mount it will resolve your issues. I just hope it wasn't over-driving the pellets (the 7.9's @ 960fps) causing the issues, ie. spiraling at distance.

[DAN 25]

Lots of good suggestions here for your problem.  I have shot more Crosman pellets than all others combined.  They are the best deal around in .22.  Excellent combination of price, quantity and quality but not the best made pellet out there. Some makers even have sample packs with a few of 5 or 6 different pellets.  As others have suggested try some heavies, JSB, H&N would be my first try.  One thing I found interesting about .177 and to a lesser extent in .22 is you can get different head sizes in some pellets.  My Gen 1 Mrod in .25 was the first pellet gun that I literally bought a stack of pellets to see which was best and plinked away the rest.  Wish I would have saved some because I just bought another .25.  Surprise it loves JSB Kings like everybody said but I had to test.  Strange looking pellets were the worst shooters.  Another suggestion is you might be getting tired after 20 shots and losing concentration.  Try shooting a ten-shot group and resting for a bit before shooting another just to see what happens.  Only change one variable at a time, kinda like getting a new scrip for eyeglasses, better or worse, change, better or worse.....

[BRAVO_4]

My RWS 460 in .22 does the EXACT SAME THING. It drives me nuts!!! The gun has gotten pretty accurate now that the barrel has settled in, but that group shifting makes me want to toss it in the creek. Only rifle of mine that does it.